C. F. Keil and Franz Delitzsch on 1 Samuel 17:26-27

1Sa 17:26-27

When David heard these words, he made more minute inquiries from the bystanders about the whole matter, and dropped some words which gave rise to the supposition that he wanted to go and fight with this Philistine himself. This is implied in the words, “For who is the Philistine, this uncircumcised one (i.e., standing as he does outside the covenant with Jehovah), that he insults the ranks of the living God!” whom he has defied in His army. “He must know,” says the Berleburger Bible, “that he has not to do with men, but with God. With a living God he will have to do, and not with an idol.”